EASA SIB 2010-06: Verification of the proper installation of Flight Control Cable - Turnbuckles

What to do

Operators should inspect turnbuckles at the next maintenance opportunity to confirm the presence and correct installation of special locking devices according to manufacturer instructions. Any anomalies such as missing locking clips, damaged safety wires, or cable loosening should be documented and reported to the aircraft manufacturer, competent authority, and EASA. Manufacturers are advised to update maintenance manuals with detailed locking procedures for turnbuckles.

Summary

EASA Safety Information Bulletin SIB No: 2010-06 is an informational document addressing the verification of proper installation of flight control cable turnbuckles on all aeroplanes, sailplanes, rotorcraft, and airships equipped with cable flight controls that use turnbuckles designed to be locked with special locking devices. The bulletin highlights a fatal accident caused by improper locking of a turnbuckle, leading to loss of flight control. It provides guidance to ensure turnbuckles are correctly locked to maintain flight safety.

What changed

This bulletin introduces recommendations for verifying that turnbuckles with special locking devices, such as locking clips, are properly installed and secured. It encourages operators to inspect turnbuckles at the next maintenance opportunity and report any anomalies to manufacturers and authorities. Additionally, it urges manufacturers to review maintenance manuals to ensure clear instructions on proper turnbuckle locking are provided.

Why it matters

Proper installation of flight control cable turnbuckles is critical to maintaining aircraft control and preventing accidents caused by cable release or loosening. For operators and maintenance organizations, following these recommendations helps avoid potential flight control failures and enhances overall safety. Compliance teams benefit from clear guidance to ensure maintenance practices meet safety standards and reduce risk.